The influence of platelet-rich plasma on myogenic differentiation.

The ability to expand and direct both precursor and stem cells towards a differential fate is considered extremely advantageous in tissue engineering. Platelet-rich plasma (PRP) possesses a milieu of growth factors and cytokines, which have the potential to have either a differentiative or proliferative influence on the cell type tested. Here, we investigated the effect of PRP on C2C12 myoblasts. A range of PRP concentrations in differentiation media was used to determine whether a concentration dependence existed, while PRP embedded in fibres of aligned electrospun polydioxanone and polycaprolactone was used to determine whether this presence of fibres would cause any differences in response. In both cases, it was found that late myogenic markers were suppressed after 7 days in culture. However, an early differentiation marker, MyoD, was upregulated during this same time period. The results from this study represent the ability of PRP to have an influence over both myogenic proliferation and differentiation, a factor which could prove useful in future studies involved with skeletal muscle tissue engineering.

Intra-rater reliability of ultrasound imaging of wrist extensor muscles in patients with tetraplegia.

OBJECTIVES: (i) To determine the intra-rater reliability and precision of the ultrasound cross-sectional area (CSA) measurements of the wrist extensors in individuals with spinal cord injury (SCI), and (ii) to determine whether tetraplegia has a negative influence on the reliability and precision for these measurements. DESIGN: A repeated-measures cross-sectional study. SETTINGS: Clinical hospital and academic settings. METHODS: The study was conducted with 20 men with SCI (9 paraplegia and 11 tetraplegia) and 10 able-bodied controls. Ultrasound images were captured of the right side extensor carpi radialis-longus (ECRL) and the extensor digitorum communis (EDC) were captured in 2 sessions separated by 48-72 hours. RESULTS: The intraclass correlation coefficients for the CSA measurements of the ECRL and EDC muscles were greater than 0.87 for all 3 groups. The standard error of the measure (SEM) ranged from 0.11-0.22 cm(2) for the ECRL and 0.13-0.27 cm(2) for the EDC. The minimal detectable change of ECL ranged from 0.16 to 0.31 cm(2) and of EDC from 0.19 to 0.38 cm(2). The group differences in muscle CSA of both muscles were found; these differences were greater than the calculated minimal detectable changes. The intraclass correlation coefficients were lower and the SEMs and minimal detectable changes were higher for the group with tetraplegia compared with the able-bodied controls and the group with paraplegia. CONCLUSIONS: This study documented substantial intra-rater reliability of measurements of the ECRL and ECD CSA by using ultrasound images, which support the use of this technique to effectively evaluate the musculoskeletal changes after SCI and during rehabilitation. Skeletal muscle atrophy in persons with tetraplegia might have a negative influence on the reliability and precision of these CSA measurements; however, these differences in reliability and precision are not of clinical significance.

A preliminary study on the potential of manuka honey and platelet-rich plasma in wound healing.

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, and a combination of PRGF and MH. Results. All three cell types demonstrated increases in cellular activity in the presence of PRGF, with further increases in activity seen in the presence of PRGF+MH. hDFs proved to be the most positively responsive cells, as they experienced enhanced proliferation, collagen matrix production, and migration into an in vitro wound healing model with the PRGF+MH-supplemented media. Conclusion. This preliminary in vitro study is the first to evaluate the combination of PRGF and Manuka honey, two products with the potential to increase regeneration individually, as a combined product to enhance dermal regeneration.

Incorporating platelet-rich plasma into electrospun scaffolds for tissue engineering applications.

Platelet-rich plasma (PRP) therapy has seen a recent spike in clinical interest due to the potential that the highly concentrated platelet solutions hold for stimulating tissue repair and regeneration. The aim of this study was to incorporate PRP into a number of electrospun materials to determine how growth factors are eluted from the structures, and what effect the presence of these factors has on enhancing electrospun scaffold bioactivity. PRP underwent a freeze-thaw-freeze process to lyse platelets, followed by lyophilization to create a powdered preparation rich in growth factors (PRGF), which was subsequently added to the electrospinning process. Release of protein from scaffolds over time was quantified, along with the quantification of human macrophage and adipose-derived stem cell (ADSC) chemotaxis and proliferation. Protein assays demonstrated a sustained release of protein from PRGF-containing scaffolds at up to 35 days in culture. Scaffold bioactivity was enhanced as ADSCs demonstrated increased proliferation in the presence of PRGF, whereas macrophages demonstrated increased chemotaxis to PRGF. In conclusion, the work performed in this study demonstrated that the incorporation of PRGF into electrospun structures has a significant positive influence on the bioactivity of the scaffolds, and may prove beneficial in a number of tissue engineering applications.

A case report on the use of sustained release platelet-rich plasma for the treatment of chronic pressure ulcers.

BACKGROUND/OBJECTIVES: Chronic pressure ulcers affect patient health, emotional state, and quality of life, causing considerable morbidity and mortality in addition to contributing to significant health care costs from lengthy hospitalizations to advanced home care and surgical care costs. The conventional treatment of these wounds can be slow due to their chronic inflammatory state and the senescence of local reparative cells. Platelet-rich plasma (PRP) therapy has been growing as a viable treatment alternative for a number of clinical applications and has potential benefit for use in chronic wounds. The sustained release of large quantities of autologous growth factors, cytokines, and other mediators found in PRP plus the favorable mononuclear cell profile of PRP may help us to stimulate wound healing and resolve chronic inflammation. METHODS: Three veterans with spinal cord injury (SCI), presenting with chronic stage IV pressure ulcers, were treated with a sustained release PRP therapy to stimulate wound healing. RESULTS: PRP treatment consistently resulted in the formation of granulation tissue and improved vascularity for each of the three patients treated, while reducing the overall ulcer area and volume. CONCLUSION: The controlled release of growth factors from PRP demonstrated a positive stimulatory effect on the healing rate of chronic pressure ulcers in individuals with SCI.

The impact of diabetes mellitus on stroke acute rehabilitation outcomes.

OBJECTIVE: To examine the impact of diabetes mellitus (DM) on functional outcomes after acute rehabilitation for cerebrovascular accident (CVA). DESIGN: A retrospective research design was used to analyze outcomes in patients with a primary diagnosis of unilateral stroke (n = 367) admitted to an urban, acute rehabilitation center in the Southeastern United States. RESULTS: Multivariable hierarchical regression revealed that DM did not contribute statistically significant variance to stroke acute rehabilitation prediction models. Rehabilitation admission functioning scores, rehabilitation length of stay, age, and stroke type were significant predictors of poststroke rehabilitation motor outcomes (r2 = 0.603) and cognitive outcomes (r2 = 0.712). Diabetes also had no significant impact on acute stroke rehabilitation lengths of stay or rehabilitation discharge setting. CONCLUSIONS: Diabetes does not seem to significantly impact short-term acute rehabilitation outcomes after stroke. Persons with diabetes who suffer a stroke seem to benefit and improve during their acute rehabilitation stay at levels equivalent to peers who are not diagnosed with diabetes. Future research should examine the impact of diabetes subtypes and undiagnosed diabetes on short- and long-term outcomes.

Does gynecologic surgery contribute to low back problems in later life? An analysis of the women's health and aging study.

OBJECTIVE: To examine whether women with potential injuries to the abdominal and pelvic musculature from past gynecologic surgery are at higher risk for low back pain (LBP). DESIGN: Cross-sectional population-based study. SETTING: Eastern region of the city and county of Baltimore, MD. PARTICIPANTS: Disabled women (N=1002) aged 65 and older, 448 of whom reported gynecologic surgery who were participants in the Women's Health and Aging Study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: LBP presence in the last year, LBP severity for the last month, and adjudicated lumbar diagnoses (disk disease, stenosis) were examined in relation to reports of surgical menopause or ovarian surgery adjusted for LBP risk factors. RESULTS: Women with surgical menopause experienced more moderate LBP (adjusted odds ratio [AOR]=1.59; 95% confidence interval [CI], 1.1-2.3) than women without surgical menopause. Women with ovarian surgery also experienced more moderate LBP than women without ovarian surgery, but this association was not statistically significant (AOR=1.39; 95% CI, 0.96-2.09). Gynecologic surgery was not associated with an increased likelihood of lumbar disk disease or stenosis. CONCLUSIONS: Surgical menopause may increase the risk of moderate LBP. Further research is needed to determine how gynecologic surgery might influence low back pathology. Abdominal and pelvic muscle rehabilitation after gynecologic surgery may provide protection from LBP later in life.

Interventions in chronic pain management. 2. New frontiers: invasive nonsurgical interventions.

UNLABELLED: Invasive nonsurgical techniques have a central role in the management of patients suffering from acute and chronic pain. This article surveys common percutaneous pain procedures: trigger point injections, intra-articular injections, spinal injections, nerve blocks, radiofrequency lesioning (thermocoagulation and pulsed-mode), epidural adhesiolysis and decompressive neuroplasty, neural mapping, intradiskal and intra-annular procedures, neuromodulation, continuous intrathecal analgesia, and deep brain stimulation. Physiatrists must understand the guiding principles behind these procedures before practicing interventional pain management. OVERALL ARTICLE OBJECTIVE: To review invasive, nonsurgical pain management procedures.

Interventions in chronic pain management. 4. Medications in pain management.

UNLABELLED: This self-directed learning module, which highlights pharmacologic approaches in the management of chronic pain, focuses on both traditional and nontraditional medications. It is part of the study guide on interventions in chronic pain management in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article highlights medication concepts, including the cyclooxygenase-2 inhibitors, opiate management of chronic pain, and neuropathic pain management; and it reviews some nontraditional approaches such as homeopathy and herbal remedies. OVERALL ARTICLE OBJECTIVE: To summarize pharmacologic approaches available for the management of chronic pain syndromes.

Interventions in chronic pain management. 5. Disease-specific issues in chronic pain.

UNLABELLED: This self-directed learning module highlights the importance of applying principles described earlier in the Study Guide to specific diseases encountered by practitioners managing chronic pain in order to administer appropriate treatment. This chapter focuses on several challenging and increasingly common maladies and attempts to delineate rationales for holistic, comprehensive care. OVERALL ARTICLE OBJECTIVE: To explore diagnostic concepts and therapeutic strategies in fibromyalgia syndrome, central pain, multiple sclerosis, complex regional pain syndrome, and postherpetic neuralgia.